Systems and methods for mounting a propulsion device with respect to a marine vessel

ABSTRACT

A system comprises an elastic mount configured to support a propulsion device with respect to a marine vessel. The elastic mount contains an electromagnetic fluid. An electromagnet is configured so that increasing an amount of electricity applied to the electromagnet increases the shear strength of the electromagnetic fluid in the elastic mount and thereby decreases elasticity of the elastic mount, and so that decreasing the amount of electricity applied to the electromagnet decreases the shear strength of the electromagnetic fluid in the elastic mount and thereby increases the elasticity of the elastic mount. A controller automatically adapts the amount of electricity applied to the electromagnet based on one or more sensed conditions so as to improve performance and/or handling of the marine vessel.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/483,214 filed Apr. 10, 2017, which is a continuation-in-partof U.S. patent application Ser. No. 14/573,347 filed Dec. 17, 2014,which are both incorporated herein by reference in their entireties.

FIELD

The present disclosure relates to propulsion systems for marine vesselsand more particularly to systems and methods for mounting a propulsiondevice with respect to a marine vessel.

BACKGROUND

The following U.S. patents are incorporated herein by reference inentirety:

U.S. Pat. No. 9,598,160 discloses a system and method control a trimdevice that positions a trimmable marine apparatus with respect to amarine vessel. A trim system is operated in an automatic mode, in whicha controller sends signals to actuate the trim device automatically as afunction of vessel or engine speed, or a manual mode, in which thecontroller sends signals to actuate the trim device in response tocommands from an operator input device. An operating speed of thepropulsion system is determined. When the operating speed has crossed agiven operating speed threshold, the trim system is subsequentlyoperated in the automatic or manual mode depending on whether theoperating speed increased or decreased as it crossed the operating speedthreshold and whether the trim system was operating in the automatic ormanual mode as the operating speed crossed the operating speedthreshold.

U.S. Pat. No. 9,481,434 discloses a mid-section housing for an outboardmotor that includes a driveshaft housing having an oil sump. An adapterplate is coupled to a top of the driveshaft housing. The adapter platehas an inner surface along which oil from an engine mounted on theadapter plate drains into the oil sump. First and second pockets areformed in an outer surface of the adapter plate on first and secondgenerally opposite sides thereof, the first and second pocketsconfigured to receive first and second mounts therein. A water jacket isformed between the inner and outer surfaces of the adapter plate. Thewater jacket extends at least partway between the inner surface of theadapter plate and each of the first and second pockets, respectively.

U.S. Pat. No. 9,205,906 discloses a mounting arrangement for supportingan outboard motor with respect to a marine vessel extending in afore-aft plane. The mounting arrangement comprises first and secondmounts that each have an outer shell, an inner wedge concentricallydisposed in the outer shell, and an elastomeric spacer between the outershell and the inner wedge. Each of the first and second mounts extendalong an axial direction, along a vertical direction that isperpendicular to the axial direction, and along a horizontal directionthat is perpendicular to the axial direction and perpendicular to thevertical direction. The inner wedges of the first and second mounts bothhave a non-circular shape when viewed in a cross-section takenperpendicular to the axial direction. The non-circular shape comprises afirst outer surface that extends transversely at an angle to thehorizontal and vertical directions. The non-circular shape comprises asecond outer surface that extends transversely at a different, secondangle to the horizontal and vertical directions.

U.S. Pat. No. 7,896,304 discloses a support system for an outboardmotor. The support system has mounts which are configured and positionedto result in an elastic center point being located closely to a rollaxis of the outboard motor which is generally vertical and extendsthrough a center of gravity of the outboard motor. The mounts arepositioned so that lines which are perpendicular to their respectivecenter lines intersect at an angle which can be generally equal toninety degrees. The mounts are positioned in non-interferingrelationship with the exhaust components of the outboard motor and itsoil sump.

U.S. Pat. No. 7,244,152 discloses an adapter system as a transitionstructure which allows a relatively conventional outboard motor to bemounted to a pedestal which provides a generally stationary verticalsteering axis. An intermediate member is connectable to a transom mountstructure having a connector adapted for mounts with central axesgenerally perpendicular to a plane of symmetry of the marine vessel.Many types of outboard motors have mounts that are generallyperpendicular to this configuration. The intermediate member provides asuitable transition structure which accommodates both of theseconfigurations and allows the conventionally mounted outboard motor tobe supported, steered, and tilted by a transom mount structure havingthe stationary vertical steering axis and pedestal-type configuration.

U.S. Pat. No. 6,942,530 discloses an engine control strategy for amarine propulsion system that selects a desired idle speed for useduring a shift event based on boat speed and engine temperature. Inorder to change the engine operating speed to the desired idle speedduring the shift event, ignition timing is altered and the status of anidle air control valve is changed. These changes to the ignition timingand the idle air control valve are made in order to achieve the desiredengine idle speed during the shift event. The idle speed during theshift event is selected so that the impact shock and resulting noise ofthe shift event can be decreased without causing the engine to stall.

U.S. Pat. No. 6,929,518 discloses a shifting apparatus for a propulsiondevice that incorporates a magneto-elastic elastic sensor which respondsto torque exerted on the shift shaft of the gear shift mechanism. Thetorque on the shift shaft induces stress which changes the magneticcharacteristics of the shift shaft material and, in turn, allows themagneto-elastic sensor to provide appropriate output signalsrepresentative of the torque exerted on the shift shaft. This allows amicroprocessor to respond to the onset of a shifting procedure ratherthan having to wait for actual physical movement of the components ofthe shifting device.

U.S. Pat. No. 6,419,534 discloses a support system for an outboard motorwhich uses four connectors attached to a support structure and to anengine system for isolating vibration from being transmitted to themarine vessel to which the outboard is attached. Each connectorcomprises an elastomeric portion for the purpose of isolating thevibration. Furthermore, the four connectors are disposed in a commonplane which is generally perpendicular to a central axis of a driveshaftof the outboard motor. Although precise perpendicularity with thedriveshaft axis is not required, it has been determined that if theplane extending through the connectors is within forty-five degrees ofperpendicularity with the driveshaft axis, improved vibration isolationcan be achieved. A support structure, or support saddle, completelysurrounds the engine system in the plane of the connectors. All of thesupport of the outboard motor is provided by the connectors within theplane, with no additional support provided at a lower position on theoutboard motor driveshaft housing.

U.S. Pat. No. 6,322,404 discloses a Hall-Effect rotational positionsensor mounted on a pivotable member of a marine propulsion system and arotatable portion of the rotational position sensor attached to a drivestructure of the marine propulsion system. Relative movement between thepivotable member, such as a gimbal ring, and the drive structure, suchas the outboard drive portion of the marine propulsion system, causerelative movement between the rotatable and stationary portions of therotational position sensor. As a result, signals can be provided whichare representative of the angular position between the drive structureand the pivotable member.

U.S. Pat. No. 6,273,771 discloses a control system for a marine vesselthat incorporates a marine propulsion system that can be attached to amarine vessel and connected in signal communication with a serialcommunication bus and a controller. A plurality of input devices andoutput devices are also connected in signal communication with thecommunication bus. A bus access manager, such as a CAN Kingdom network,is connected in signal communication with the controller to regulate theincorporation of additional devices to the plurality of devices insignal communication with the bus. The controller is connected in signalcommunication with each of the plurality of devices on the communicationbus. The input and output devices can each transmit messages to theserial communication bus for receipt by other devices.

U.S. Pat. No. 4,893,800 discloses a power unit mount that includes ahousing in which first and second electrode bodies are suspended andwhich is filled with a fluid which exhibits a change in viscosity when avoltage is applied there across. The control of the voltage applicationis determined by a control circuit which is operatively connected to aplurality of sensors which include an engine speed sensor, a road wheelspeed sensor, a relative displacement sensor and an absolutedisplacement sensor. A variant includes a solenoid powered vibrationgenerator which can be energized under predetermined conditions in amanner to improve vibration attenuation.

SUMMARY

This Summary is provided to introduce a selection of concepts that arefurther described below in the Detailed Description. This Summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

The present disclosure arose during continuing research and developmentof mounts, mounting arrangements and methods of making mountingarrangements for supporting propulsion devices such as outboard motorswith respect to marine vessels. In certain examples, a system is forsupporting a propulsion device with respect to a marine vessel. Thesystem comprises an elastic mount configured to support the propulsiondevice with respect to the marine vessel. The elastic mount contains anelectromagnetic fluid. An electromagnet is configured so that increasingan amount of electricity applied to the electromagnet increases theshear strength of the electromagnetic fluid in the elastic mount andthereby decreases elasticity of the elastic mount. The electromagnet isfurther configured so that decreasing the amount of electricity appliedto the electromagnet decreases the shear strength of the electromagneticfluid in the elastic mount and thereby increases the elasticity of theelastic mount.

A controller automatically adapts the amount of electricity applied tothe electromagnet based on one or more sensed conditions so as toimprove performance and/or handling of the marine vessel. In oneexample, the controller increases the amount of electricity applied tothe electromagnet so as to reduce oscillation of the propulsion deviceresulting from hydrodynamic loading. In another example, the controllerincreases the amount of electricity applied to the electromagnet duringrapid deceleration of the marine vessel so as to decrease the likelihoodof hooking. In another example, the controller decreases the amount ofelectricity applied to the electromagnet during a rapid acceleration ofthe marine vessel so as to increase the elasticity of the elastic mountto allow further trim-in of the propulsion device. Corresponding methodsare disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described with reference to the followingfigures. The same numbers are used throughout the figures to referencelike features and like components.

FIG. 1 is taken from U.S. Pat. No. 7,244,152 and is a perspective viewof a prior art propulsion device and prior art mounting devices formounting the propulsion device to a marine vessel.

FIG. 2 is schematic depiction of a system according to the presentdisclosure for supporting a propulsion device with respect to a marinevessel.

FIGS. 3-5 are flow charts depicting exemplary methods according to thepresent disclosure.

FIGS. 6-7 depict a first example of an elastic mount according to thepresent disclosure.

FIGS. 8-11 depict a second example of an elastic mount according to thepresent disclosure.

FIGS. 12-14 depict a third example of an elastic mount according to thepresent disclosure.

FIGS. 15A-15C illustrate a trimmable propulsion device mounted to amarine vessel.

FIG. 16 depicts one embodiment of a propulsion system for a marinevessel involving three propulsion devices, each connected to the marinevessel via a mount system that includes two elastic mounts.

FIGS. 17A and 17B depict oscillation measurements on a propulsion deviceand exemplary corresponding power adjustments to an electromagnetchanging elasticity of an elastic mount.

FIGS. 18-23 depict various embodiments of methods, or portions thereof,for controlling an elastic mount configured to support a propulsiondevice with respect to a marine vessel.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is taken from the incorporated U.S. Pat. No. 7,244,152 anddepicts an arrangement for mounting a propulsion device 10 to a marinevessel via a support bracket 14, which is commonly referred to in theart as a transom bracket. Details regarding the conventional transombracket are provided in the '152 patent. As is conventional, a pluralityof elastic mounts 16 a-16 b are disposed between connection points ofthe propulsion device 10 and marine vessel, including at an adapterplate 18 (see 16 a) and at a drive shaft housing 20 (see 16 b) of thepropulsion device 10.

Through research and development, the present inventors have endeavoredto provide propulsion systems for marine vessels having improved noise,vibration and harshness characteristics. Also, the present inventorshave endeavored to provide a marine propulsion system having increasedpower, speed, and acceleration, improved handling and tighter transompackaging. Through such research and development, the present inventorsfound that current elastomeric mounts have functional limitations thatforce engineering compromises regarding overall package size, layout,engine design, and noise, vibration and harshness characteristics. Also,the inventors found that prior art mounts typically are designed for anentire family of propulsion devices having similar characteristics andtypically are not adjustable or vessel-specific. During research anddevelopment, the present inventors determined that it would be desirableto provide systems and methods that semi-actively and/or actively adaptthe elasticity of the mounts based upon current characteristics and/orconditions of the propulsion device and/or marine vessel to therebyactively and/or semi-actively control displacement of the propulsiondevice during marine vessel travel.

FIG. 2 schematically depicts a system 28 according to the presentdisclosure for supporting the propulsion device 10 with respect to themarine vessel 12. The system 28 includes a controller 30 that isprogrammable and includes a computer processor 32, software 34, a memory(i.e., computer storage) 36 and an input/output (interface) device 38.The processor 32 loads and executes software 34, which can be stored inthe memory 36. Executing the software 34 controls the system 28 tooperate as described herein in further detail below. The processor 32can comprise a microprocessor and/or other circuitry that receives andexecutes software 34. The processor 32 can be implemented within asingle device, but can also be distributed across multiple processingdevices and/or sub-systems that cooperate in executing programinstructions. Examples include general purpose central processing units,application specific processors, and logic devices, as well as any otherprocessing device, combinations of processing devices, and/or variationsthereof. Likewise, the controller 30 may be a single device, or may bemultiple devices cooperating to control the propulsion device(s) 10 andother aspects of the marine vessel 2. In one example described herein(FIG. 16), the controller 30 is embodied as a helm control module (HCM)30 a and one or more engine control modules (ECMs) 30 b that cooperateto provide the control operations described herein. The controller 30can be located anywhere with respect to the propulsion device 10 andmarine vessel 12 and can communicate with various components of thesystem 28 via wired and/or wireless links. The controller 30 can haveone or more microprocessors that are located together or remotely fromeach other in the system 28 or remotely from the system 28.

The memory 36 can include any storage media that is readable by theprocessor 32 and capable of storing software 34. The memory 36 caninclude volatile and/or nonvolatile, removable and/or non-removablemedia implemented in any method or technology for storage ofinformation, such as computer readable instructions, data structures,program modules, or other data. The memory 36 can be implemented as asingle storage device but may also be implemented across multiplestorage devices or sub-systems. The memory 36 can further includeadditional elements, such as a controller capable of communicating withthe processor 32. Examples of storage devices include random accessmemory, read only memory, magnetic discs, optical discs, flash memorydiscs, virtual and/or non-virtual memory, magnetic cassettes, magnetictape, magnetic disc storage, or other magnetic storage devices, or anyother medium which can be used to store the desired information and thatmay be accessed by an instruction execution system, as well as anycombination or variation thereof, or any other type of storage media. Insome implementations, the storage media can be a non-transitory storagemedia.

The input/output device 38 can include any one of a variety ofconventional computer input/output interfaces for receiving electricalsignals for input to the processor 32 and for sending electrical signalsfrom the processor 32 to various components of the system 28.

The controller 30, via the input/output device 38, communicates withcomponents of the propulsion device 10 and components of the system 28via communication links, which as mentioned herein above can be wired orwireless links. As explained further herein below, the controller 30 iscapable of monitoring and controlling operational characteristics of thepropulsion device 10 by sending and/or receiving control signals via thevarious links, such as exemplified in FIGS. 2 and 16. Although the linksare each shown as a single link, the term “link” can encompass one or aplurality of links that are each connected to one or more of thecomponents of the system 28.

The systems and methods described herein may be implemented with one ormore computer programs executed by one or more control modules, eachhaving one or more processors. The computer programs includeprocessor-executable instructions that are stored on non-transitorytangible computer readable media. The computer programs may also includestored data, such as look up tables or value maps, providing valuesbased on one or more input variables.

It should be noted that the extent of the connections and communicationlinks may in fact be one or more shared connections, or links, amongsome or all of the components in the system. In one example, thecommunication links may be provided by a single controller area network(CAN) bus, but other types of links could be used. Moreover, thecommunication link lines are meant only to demonstrate that the variouscontrol elements, sensor elements, etc. are capable of communicatingwith one another, and do not represent actual wiring connections betweenthe various elements, nor do they represent the only paths ofcommunication between the elements. Additionally, the system 28 mayincorporate various types of communication devices and systems, and thusthe illustrated communication links may in fact represent variousdifferent types of wireless and/or wired data communication systems.

Each propulsion device is connected to the marine vessel 2 by a mountsystem 29, wherein each mount system 29 includes one or more elasticmounts 160 a, 160 b (FIG. 16). Mounts 160 a, 160 b are provided with anelectromagnet 22. Each mount 160 a, 160 b contains an electromagneticfluid 24. In this example, the electromagnet 22 is located in therespective mount 160 a, 160 b; however as will be evident from theexamples below, the electromagnet 22 can alternately be located remotefrom the respective mount 160 a, 160 b. A power source 26, which can bea conventional battery or any other suitable power source, is configuredto provide an amount of electricity (e.g., voltage, current) to theelectromagnet 22. As described further herein below with respect toFIGS. 6-14, increasing the amount of electricity provided to theelectromagnet 22 increases the shear strength of the electromagneticfluid 24, thereby decreasing elasticity of the mount 160 a, 160 b.Decreasing the amount of electricity provided to the electromagnet 22decreases the shear strength of the electromagnetic fluid 24, therebyincreasing the elasticity of the mount 160 a, 160 b. Thus, changing theamount of electricity provided to the electromagnet 22 changes thedamping characteristics of the mount 160 a, 160 b. This concept willbecome more apparent in view of the examples provided herein below withrespect to FIGS. 6-14. Generally, application of a electricity across anelectromagnetic fluid to alter damping characteristics of a suspensiondevice is described, for example, in U.S. Pat. No. 4,893,800, which isincorporated herein by reference. A pressure sensor 42 is connected toeach mount 160 a, 160 b and is configured to sense the pressure of theelectromagnetic fluid 24 in the mount 160 a, 160 b and communicate thisinformation to the controller 30. The type and packaging of pressuresensor 42 can vary and in some examples includes a conventional pressuretransducer. The controller 30 is provided with an input from a vesselspeed sensor 41. The vessel speed sensor 41 may be, for example, a pitottube sensor, a paddle wheel type sensor, or any other speed sensorappropriate for sensing the actual speed of the marine vessel.Alternatively or additionally, the vessel speed may be obtained bytaking readings from a GPS device 43, which calculates speed bydetermining how far the vessel has traveled in a given amount of timeaccording to known methods.

An engine speed sensor 44 is configured to sense a current engine speedof the propulsion device 10. In certain examples, the engine speedsensor 44 senses rotations per minute (RPM) of the engine. The type andlocation of engine speed sensor 44 can vary and in one example is a HallEffect or variable reluctance sensor located near the encoder ring ofthe engine. Such an engine speed sensor 44 is known in the art andcommercially available, for example, from CTS Corporation or Delphi.

A shift position sensor 46 is configured to sense a current gear state(e.g. position) of a clutch or transmission associated with thepropulsion device 10. In some examples, the shift position sensor 46senses a current position of a shift linkage or lever positionassociated with a conventional shift/throttle control lever. The gearstate that is sensed by the shift position sensor 46 is communicated tothe controller 30. In one typical example known in the art, the gearstate may be one of a forward shift position where the propulsion devicepropels the marine vessel in a forward direction, a reverse shiftposition where the propulsion device propels the marine vessel in arear-ward direction, and a neutral state where no propulsion force isexerted. The type and location of shift position sensor 46 can vary. Inone example, the shift position sensor 46 includes a rotary encoder,which may be a potentiometer and an electronic converter, such as ananalog to digital converter that outputs discrete analog to digital(ADC) counts that each represents a position of the noted shift linkageor lever position. Such potentiometer and electronic convertercombinations are known in the art and commercially available, forexample, from CTS Corporation.

Similarly, a throttle position sensor 49 is configured to sense acurrent throttle demand, which is the user demand commanded by an inputdevice, such as a throttle control lever. In some examples, the throttleposition sensor 49 senses a current position of a throttle linkage or aposition of a throttle control lever 39. The output of the throttleposition sensor 49 is sent to the controller 30 which interprets it as athrottle demand input for controlling various subsystems of the one ormore propulsion devices 10, including for fueling, air intake, spark,etc. For example, the throttle position sensor 49 may include apotentiometer and an electric converter, such as an analog to digitalconverter that outputs discrete ADC counts that each represents aposition of the noted throttle linkage or throttle control leverposition.

An engine load sensor 48 is configured to sense a current engine load ofthe propulsion device 10 and communicate this information to thecontroller 30. The type of engine load sensor 48 can vary. In certainexamples, the engine load sensor 48 is provided by the noted enginespeed sensor 44 in combination with a throttle valve position sensorthat senses position of a throttle valve associated with the engine onthe propulsion device 10. The type of throttle position sensor can vary.One example of a throttle positon sensor can be a wiper-type sensor,which can be located on the body of the noted throttle valve and iscommercially available from Cooper Auto or Walbro. Engine load can thusbe provided to controller 30 via comparison of the outputs of the notedthrottle position sensor and the engine speed sensor 44. In otherexamples, the load sensor may involve a manifold absolute pressure (MAP)sensor, wherein the engine load is determined based on the manifoldpressure.

A steering angle sensor 50 is configured to sense a current steeringangle of the propulsion device 10 with respect to the marine vessel andprovide this information to the controller 30. The type of steeringangle sensor 50 can vary. In certain examples, the steering angle sensor50 can include an encoder mounted on along a vertical steering axis ofthe propulsion device 10, as is conventional.

The system may further include a steering wheel position sensor 51configured to sense the angular position of a steering wheel 31 steeringthe marine vessel 2. In one known example, the steering wheel positionsensor 51 is a rotary encoder outputting ADC counts representing aposition of the steering wheel 31. In other examples, the steering wheelposition sensor 51 may instead be positioned on steering linkage betweenthe steering wheel 31 and steering actuators associated with thepropulsion device(s) 10.

A trim position sensor 52 is configured to sense a current trim positonof the propulsion device 10 and provide this information to thecontroller 30. Trim control systems are known in the art, such as thatexemplified and described at U.S. Pat. No. 9,598,160 incorporated hereinby reference. FIGS. 15A-15C illustrate an example of a marine vessel 2having a trim system for controlling an the angle at which thepropulsion devices are supported with respect to the marine vessel 2. Inthis example, the marine vessel 2 is equipped with a propulsion device10, such as the outboard motor shown, on its transom 105. The propulsiondevice can be trimmed to different angles with respect to the transom105 via trim devices 127, such as hydraulic cylinders having one endcoupled to the transom 105 of the vessel 2 and the other end coupled tothe outboard motor as known to those having ordinary skill in the art.In FIG. 15A, the propulsion device 10 is shown in a neutral (level) trimposition, in which the propulsion device 10 is in more or less of avertical position. This can be seen by comparing centerline CL of thepropulsion device 10 with vertical line V, where the two lines areparallel. In FIG. 15B, the propulsion device 10 is shown in a trimmed-in(sometimes referred to as trimmed down) position. In other words, thelines CL and V will intersect below where the propulsion device 10 isconnected to the transom 105. This may be referred to as a negative trimangle (NT) according to an exemplary convention. In FIG. 15C, thepropulsion device 10 is shown in a trimmed out (sometimes referred to astrimmed up) position. The lines CL and V will intersect above the driveunit's connection point to the transom 105. This may be referred to as apositive trim angle (PT).

The positions in FIGS. 15A and 15B are generally used when the marinevessel 2 is operating at slower speeds. For example, the trim positionshown in FIG. 15A is often used when the marine vessel 2 is in ajoysticking mode or is docking. The trim position in FIG. 15B is oftenused during launch of the marine vessel 2, before the marine vessel 2has gotten up to speed and on plane. In contrast, the trim positionshown in FIG. 15C is often used when the marine vessel 2 is on plane andhigh speeds are required. At high speeds, the trim position shown inFIG. 15C causes the bow 109 of the marine vessel 2 to rise out of thewater as shown. Trim position is often expressed as a percentage from 0%to 100%, where 0% is the fully trimmed-in position and 100% is the fullytrimmed out position. The type of trim position sensor 52 can vary. Incertain examples, the trim position sensor 52 includes an encoderpositioned along a trim axis of the propulsion device 10.

A vessel motion sensor 54 is configured to measure acceleration and/orangular position of the marine vessel and provides this information tothe controller 30. In one example, the motion sensor 54 includes aconventional 3-axis accelerometer and/or 3-axis gyroscope fixed to themarine vessel 2. In certain embodiments the motion sensor may alsoinclude a magnetometer. For example, the vessel motion sensor 54measure, a vessel angle of the marine vessel 2 with respect tohorizontal, such as to track the angular position of the marine vessel 2as it banks during a turn at high speed. An underwater impact sensor 56is provided for sensing a future impact to the propulsion device 10 andcommunicating this information to the controller 30. They type of impactsensor 56 can vary and can include, for example, a sonar system, lasersystem, and/or the like.

A motion sensor 57 is configured to sense motion of the propulsiondevice 10 with respect to the marine vessel, for example vibration ofthe propulsion device 10 caused by environmental forces including windand/or waves. The motion sensor 57 can be mounted on the propulsiondevice 10. The type of motion sensor 57 can vary and can include aglobal navigation satellite device with an internal measurement unitthat collects angular velocity and linear acceleration, which data issent to the controller 30. This type of motion sensor is well known inthe art, an example is commercial available from XSENS, Product No.MTi-G-710. In other embodiments, the motion sensor 57 may include on ormore of a 3-axis accelerometer, a 3-axis gyroscope, and/or amagnetometer based upon which motion and/or position of the marinevessel is determined in 3-dimensional space.

The system 28 also includes a user input device 58 for inputting usercommands to the controller 30. The user input device 58 can include acombination shift/throttle lever 39, a steering wheel 31, and/or ajoystick. Other types of input devices such as a button, switch,touchscreen, and/or the like can also be used in addition to or insteadof these conventional devices.

Advantageously, as described further herein below, the controller 30 isprogrammed to actively and automatically adapt the amount of electricitythat is supplied to the electromagnets 22 from the power source 26 basedupon one or more conditions of the system 28. In some examples, thememory stores one or more thresholds to which the controller 30 comparescurrent sensed values and then controls the amount of electricityaccordingly. In some examples, the memory 36 stores one or more map(s)60 that correlates the noted one or more conditions of the system 28 tothe amount of electricity. For example, a base map 60 may be stored inmemory 36 for controlling the electricity, power, to one or more of theelectromagnets 22 under normal operating conditions, and additional mapsor control algorithms may be utilized upon detection of certain, definedoperating conditions requiring specialized control. The controller 30 isconfigured to follow the map 60 to apply a programmed amount ofelectricity based upon current sensed values. In addition oralternately, the memory 36 stores a protocol that is followed by thecontroller 30 to thereby adapt the amount of electricity. In otherwords, the controller 30 is programmed to control the power source 26 tochange the amount of electricity according to the map 60 and/or otherprotocol stored in the memory. The type of conditions upon which thecontroller 30 adapts the amount of electricity can vary and in someexamples the controller 30 can be programmed to adapt the amount ofelectricity based upon more than one condition considered incombination. The conditions upon which the controller 30 adapts theamount of electricity can include characteristics of the propulsiondevice 10 and/or marine vessel 2. These conditions typically do not varyand can be calibrated in the controller 30 during setup of the system.The conditions upon which the controller 30 adapts the amount ofelectricity can include operational characteristics of the marinevessel, including speed, acceleration, steering angle, motion, throttledemand, and/or the like. The controller 30 can be configured to adaptthe amount of electricity upon the occurrence of one or more of thesetypes of operational characteristics (i.e. in real-time), as furtherdescribed herein below.

In some examples, the condition of the system upon which the controller30 adapts the amount of electricity includes a pressure of theelectromagnetic fluid 24 in the mount 160 a, 160 b. The pressure sensor42 is configured to sense the pressure of the electromagnetic fluid 24in the mount 160 a, 160 b and communicate this information to thecontroller 30, which compares the sensed pressure to the map 60 tothereby identify an amount of electricity to be applied to theelectromagnet 22. Thereafter, the controller 30 controls the powersource 26 to apply that amount of electricity. In some examples, thecontroller 30 can be configured to decrease the amount of electricitywhen the pressure of the electromagnetic fluid 24 exceeds a pressurethreshold that is calibrated and stored in the memory 36. The controller30 can be programmed to compare the pressure of the electromagneticfluid 24, as sensed by the pressure sensor 42, to the stored pressurethreshold, and thereafter control the power source 26 to decrease theamount of electricity when the pressure of the electromagnetic fluid 24exceeds the pressure threshold. Thus this feature can protect the mount160 a, 160 b from over pressure.

The controller 30 can also be programmed to alert an operator of themarine vessel that the propulsion device 10 is experiencing high staticloading, for example due to rough water and/or high speed operations. Insome examples, the controller 30 can be programmed to store thisinformation in the memory 36 for service and/or warranty purposes. Thisfeature can also actively monitor and adjust the amount of electricityduring travel of the marine vessel according to the map 60 and/oranother protocol saved in the memory 36, thus providing the system 28with ride characteristics that are selected by the calibrator and/or theuser.

In certain examples, the condition of the system can include a currentstate of the propulsion device 10. In these examples, the shift positionsensor 46 is configured to sense the current gear state of thepropulsion device 10 and communicate this information to the controller30. Based upon this information, the controller 30 is configured tocontrol the power source 26 to apply an appropriate amount ofelectricity to the electromagnet 22, as determined for example by themap 60 and/or another protocol saved in the memory 36. For example, itcan be desirable to limit displacement of the propulsion device 10during forward and/or reverse shift positon of propulsion device 10 toprovide certain ride characteristics, while it can also be desirable toallow displacement of the propulsion device 10 during neutral state ofthe propulsion device to limit noise, vibration and/or harshness. Inthis non-limiting example, the controller 30 can be programmed toincrease the amount of electricity during forward and reverse shiftpositions and decrease the amount of electricity during neutral state.

In certain examples, the condition of the system 28 includes a currenttrim position of the propulsion device 10. In these examples, the notedtrim position sensor 52 is configured to sense the current trim positionof the propulsion device 10 and communicate this information to thecontroller 30. Based upon this information, the controller 30 isprogrammed to control the power source 26 to apply a certain amount ofelectricity to the electromagnet 22, as determined for example by themap 60 or other protocol saved in memory 36. In certain examples, thecontroller 30 can be programmed to increase the amount of electricitywhen the current trim positon of the propulsion device 10 exceeds a trimposition threshold stored in the memory 36. In this non-limitingexample, the controller 30 is capable of decreasing the resiliency ofthe mounts 160 a, 160 b when the propulsion device 10 is fully trimmedout, which typically happens when the marine vessel 12 is docked.

In certain examples, the condition of the system 28 can include a futureor predicted impact to the propulsion device 10. In these examples theimpact sensor 56 is configured to sense the future or predicted impactto the propulsion device 10 and communicate this information to thecontroller 30. Based upon this information, the controller 30 isprogrammed to control the power source 26 to adapt the amount ofelectricity. In some non-limiting examples, the controller 30 can beprogrammed to decrease the amount of electricity when an impact to thepropulsion device 10 is predicted, thus allowing the propulsion device10 to deflect when hit. This can protect the propulsion device 10 frombeing damaged.

In certain examples, the condition of the system 28 can include acurrent engine load of the propulsion device 10. In these examples, theengine load sensor 48 is configured to sense the current engine load ofthe propulsion device 10 and communicate this information to thecontroller 30. The controller 30 is configured to control the powersource 26 to adapt the amount of electricity based upon, for example,the noted map 60 or other protocol saved in the memory 36. Thecontroller 30 thus advantageously can be calibrated to adjust the ridecharacteristics of the propulsion device 10 during translation of themarine vessel 12.

In some examples, the condition of the system 28 can include the currentengine speed of the propulsion device 10. In these examples, the enginespeed sensor 44 is configured to sense the current engine speed of thepropulsion device 10 and communicate this information to the controller30, which in turn is configured to control the power source 26 basedupon, for example the protocol set forth in the map 60 stored in thememory 36. In some examples, the controller 30 is programmed to decreasethe amount of electricity when the current engine speed is below anengine speed threshold saved in the memory 36. In certain examples, thecontroller 30 is configured to increase the amount of electricity whenthe current engine speed is above an engine speed threshold stored inthe memory 36. The controller 30 thus advantageously can be calibratedto adjust the ride characteristics of the propulsion device 10 duringtranslation of the marine vessel 12.

In certain examples, the condition of the system 28 can include acurrent steering angle of the propulsion device 10. In these examples,the steering angle sensor 50 is configured to sense the current steeringangle and communicate this information to the controller 30. In turn,the controller 30 is configured to control the power source 26 tocontrol the amount of electricity applied to the electromagnet 22. Insome examples, the controller 30 is configured to increase the amount ofelectricity when the current steering angle of the propulsion device 10is outside of a stored range.

In certain examples, the condition of the system 28 includes andoff-state of an internal combustion engine associated with thepropulsion device 10. In these examples, the controller 30 can beprogrammed to increase the amount of electricity to lock the mount 160a, 160 b in position when the off state of the engine occurs.

As shown in FIG. 2, the system 28 can further include the user inputdevice 58 for inputting a desired state of elasticity of the mount 160a, 160 b. In these examples, the controller 30 can be configured toadapt the amount of electricity to achieve the desired state ofelasticity of the mount 160 a, 160 b, as for example according to themap 60 or other protocol saved in the memory 36. The controller 30 canalso be configured to control a display device 53 for displaying thecondition of the mount 160 a, 160 b to an operator of the system 28.

FIGS. 3-5 and 17-23 depict non-limiting exemplary methods according tothe present disclosure.

As shown in FIG. 3, at step 62, one or more of the above noted sensorsis configured to sense one or more conditions of the system 28 andcommunicate this information to controller 30. At step 64, thecontroller 30 is configured to compare the sensed condition(s) to themap 60 or to another protocol stored in the memory 36. At step 66, thecontroller 30 is configured to adapt the amount of electricity that isapplied by the power source 26 to the electromagnet 22.

FIG. 4 depicts an example wherein the pressure sensor 42 is utilized tosense pressure of electromagnetic fluid 24 in the electromagnet 22, atstep 68. At step 70, the controller 30 is configured to compare thepressure of the electromagnetic fluid 24 to a pressure threshold that isstored in the memory 36. If the pressure exceeds the pressure threshold,at step 72, the controller 30 is programmed to control the power source26 to reduce the amount of electricity that is applied to theelectromagnet 22.

In FIG. 5, at step 76, the trim position sensor 52 senses the trimpositon of the propulsion device 10 with respect to the marine vessel12. At step 78, the controller 30 is configured to compare the trimposition that is sensed by the trim position sensor 52 to a thresholdthat is stored in the memory 36. If the trim position exceeds thethreshold, the controller 30 is configured to control the power source26 at step 80 to increase the amount of electricity applied to theelectromagnet 22.

In certain examples, the map 60 can correlate trim and steeringpositions for specific tight transom installations, having limited spacefor movement of the propulsion device 10. The map 60 can dictate “pinch”points where the amount of electricity needs to be adjusted to minimizedeflection of the mounts 160 a, 160 b and thus prevent cowl collision.

In other examples, the controller 30 can actively monitor for highinternal mount pressure and/or motion, and adjust the amount ofelectricity during travel of the marine vessel, providing restriction onthe amount of deflection of the mounts 160 a, 160 b to prevent cowlcollision in tightly packaged transom arrangements.

In other words, the system 28 can be configured to allow tightly packedtransom arrangements, while still accomplishing functional goals such aspower, speed and acceleration. The inventors have recognized that it isdesirable to provide marine propulsion systems having increased power,speed, and acceleration; however this often requires the designer to addlarger propulsion devices and/or multiple propulsion devices to thesystem. As stated above, the inventors have also recognized that it isdesirable to provide marine propulsion systems having a smallerfootprint, i.e. smaller package size, design and/or layout. Theseinterests compete with each other and thus present design challenges.The larger the size and/or number of propulsion devices, the greater thepower, speed and acceleration. However when larger propulsion devicesand/or multiple propulsion devices are added, it becomes difficult tomeet small package size, design and layout requirements.

During operation of a marine propulsion system, environmental forces onthe marine propulsion devices, such as wind and/or waves, will normallycause the marine propulsion devices to vibrate and/or otherwise movewith respect to surrounding structures, such as the hull of marinevessel and/or adjacent marine propulsion devices on the transom. Also,each marine propulsion device is typically steerable about a steeringaxis between port and starboard orientations. As such, for every marinepropulsion system layout, there is a minimum amount of spacing requiredbetween the propulsion device and adjacent structures. That is, thedesigner must include enough space between each propulsion device on thetransom to accommodate the above-mentioned vibration and steeringmovements, and specifically to avoid collision between the propulsiondevice and adjacent structures.

Through research and experimentation, the present inventors havedetermined that it is possible to utilize the above-described systems toachieve higher performance with tighter tolerances, i.e., packaging thepropulsion devices with less surrounding space. More specifically, thepresent inventors have realized that the amount of spacing that isactually required in the marine propulsion system layout variesdepending upon the operating condition of the system. For example, whenthe marine propulsion system is inoperative or operating at idle and/orat relatively low speeds, minimal environmental forces will typicallyimpact the propulsion device and thus only a relatively small amount ofspacing is normally required to accommodate vibration or other movementscaused by environmental forces. On the other hand, when the marinepropulsion system is operating at relatively high speeds, it often willencounter more forceful environmental forces, such as high wind and/orwaves, and thus a relatively large amount of spacing is required toprevent collision between the propulsion device and adjacent structures.Other factors, such as the steering angle of the propulsion device willalso impact the necessary spacing between the propulsion device andadjacent structures. When the propulsion device is in a straight-aheadorientation, environmental forces are less likely to cause movement ofthe propulsion device and adjacent structures. On the other hand, whenthe propulsion device is steered into an extreme turning orientation, itwill move closer to adjacent structures, thus making it more likely thatenvironmental forces will cause movements of the propulsion device thatresult in a collision with the adjacent structure.

Based upon these realizations, the present inventors developed systemsand methods that automatically adapt the amount of electricity appliedto the electromagnet during operation (e.g. translation) of the marinevessel—so as to reduce the likelihood that the propulsion device impactsan adjacent structure on the marine vessel as a result of motion of thepropulsion device caused by environmental forces including wind andwaves. Further examples are provided herein below.

In some examples, the controller 30 is programmed to automatically adaptthe amount of electricity applied to the electromagnet 22 duringoperation of the marine vessel so as to reduce the above-describedlikelihood that the propulsion device 10 impacts an adjacent structureon the marine vessel as a result of motion of the propulsion device 10caused by environmental forces including wind and waves. The “adjacentstructure” can be another propulsion device 10 on the marine vesseland/or the hull of the marine vessel itself and/or any other adjacentstructure. The controller 30 is configured to automatically increase theamount of electricity applied to the electromagnet 22 when it determinesthat the propulsion device 10 has become more likely to impact theadjacent structure. The controller 30 is further programmed toautomatically decrease the amount of electricity applied to theelectromagnet 22 when it determines that the propulsion device 10 hasbecome less likely to impact the adjacent structure. The way in whichthe controller 30 determines the likelihood of impact to the propulsiondevice 10 can vary. In some examples, the controller 30 is programmed todetermine whether the propulsion device 10 has become more or lesslikely to impact the adjacent structure based at least in part upon thepresent steering angle of the propulsion device 10. In this example, thecontroller 30 is programmed to increase the amount of electricityapplied to the electromagnet 22 when the present steering angle becomesgreater than (i.e. further away from a straight-ahead orientation) athreshold steering angle value stored in the memory 36. The controller30 is further programmed to decrease the amount of electricity appliedto the electromagnet 22 when the present steering angle becomes lessthan (i.e. closer to the straight-ahead orientation) the thresholdsteering angle value stored in the memory 36. The threshold steeringangle is a value that can be calibrated by the engine designer throughtrial and error or based on historical data for the same or similarlayouts.

In some examples, the controller 30 is programmed to determine whetherthe propulsion device 10 has become more or less likely to impact theadjacent structure based at least in part upon a present motioncharacteristic of the propulsion device with respect to the marinevessel. In this example, the controller 30 is programmed to increase theamount of electricity applied to the electromagnet 22 when the presentmotion (e.g. vibration) of the propulsion device 10 becomes greater thana threshold motion value stored in the memory 36. The controller 30 isfurther programmed to decrease the amount of electricity applied to theelectromagnet 22 when the present motion (e.g. vibration) of thepropulsion device 10 becomes less than the threshold motion value storedin the memory 36. The threshold motion value is a value that can becalibrated by the engine designer through trial and error or based onhistorical data for the same or similar layouts.

In some examples, the controller 30 is programmed to determine whetherthe propulsion device 10 has become more or less likely to impact theadjacent structure based at least in part upon the present speed of theengine. In this example, the controller 30 is configured to increase theamount of electricity applied to the electromagnet 22 when the presentspeed of the engine becomes greater than a threshold engine speed valuestored in the memory 36. The controller 30 is configured to decrease theamount of electricity applied to the electromagnet 22 when the presentspeed of the engine becomes less than the threshold engine speed valuestored in the memory 36. The threshold engine speed value is a valuethat can be calibrated by the engine designer through trial and error orbased on historical data for the same or similar layouts. Similar tothese examples, in other examples, the controller 30 can be programmedto determine whether the propulsion device 10 has become more or lesslikely to impact the adjacent structure based at least in part upon thepresent engine load, i.e. how the present engine load compares to athreshold engine load stored in the memory 36.

In some examples, the controller 30 is programmed to determine whetherthe propulsion device 10 has become more or less likely to impact theadjacent structure based at least in part upon the state of accelerationof the propulsion device 10. In this example, the controller 30 isprogrammed to increase the amount of electricity applied to theelectromagnet 22 when the present state of acceleration of thepropulsion device 10 becomes greater than a threshold acceleration valuestored in the memory 36. The controller 30 is configured to decrease theamount of electricity applied to the electromagnet 22 when the presentstate of acceleration of the propulsion device 10 becomes less than thethreshold acceleration value stored in the memory 36. The thresholdacceleration value is a value that can be calibrated by the enginedesigner through trial and error or based on historical data for thesame or similar layouts.

In some examples, the controller 30 is programmed to determine whetherthe propulsion device 10 has become more or less likely to impact theadjacent structure based at least in part upon the present trim positionof the propulsion device 10. In this example, the controller 30 isprogrammed to increase the amount of electricity applied to theelectromagnet 22 when the present trim position of the propulsion device10 becomes greater than a threshold trim position value stored in thememory 36. The controller 30 is configured to decrease the amount ofelectricity applied to the electromagnet 22 when the present trimposition of the propulsion device 10 becomes less than the thresholdtrim position value stored in the memory 36. The threshold trim positionvalue is a value that can be calibrated by the engine designer throughtrial and error or based on historical data for the same or similarlayouts.

In some examples, the controller 30 is programmed to operate based onany combination of the above-mentioned values. For example, thecontroller 30 can be programmed to determine the likelihood that thepropulsion device 10 impacts the adjacent structure on the marine vesselbased at least in part on a combination of the present speed of anengine associated with the propulsion device 10 and the present motionof the propulsion device 10 with respect to the marine vessel. Forexample, the map 60 stored in the memory 36 can correlate speed of theengine and motion of the propulsion device 10 with respect to the marinevessel to an amount of electricity applied to the electromagnet 22.Based on the present speed of the engine and motion of the propulsiondevice 10, the map 60 will inform the controller 30 regarding thelikelihood that the propulsion device 10 impacts the adjacent structureon the marine vessel. The controller 30 can thus be programmed tocontrol the power source 26 in accordance with the map 60. The values ofthe map 60 can be calibrated by the engine designer through trial anderror or based on historical data for the same or similar layouts.

In other examples, the controller 30 can be programmed to determine thelikelihood that the propulsion device 10 impacts the adjacent structureon the marine vessel based at least in part on a combination of thepresent speed of an engine associated with the propulsion device 10 anda present steering angle of the propulsion device 10. In this example,the map 60 stored in the memory 36 correlates speed of the engine andsteering angle of the propulsion device 10 to an amount of electricityapplied to the electromagnet 22. Based on the present speed of theengine and present steering angle of the propulsion device 10, the map60 will inform the controller 30 regarding the likelihood that thepropulsion device 10 impacts the adjacent structure on the marinevessel. The controller 30 can thus be programmed to control the powersource 26 in accordance with the map 60. The values of the map 60 can becalibrated by the engine designer through trial and error or based onhistorical data for the same or similar layouts.

It will thus be recognized that the present disclosure provides methodsfor supporting a propulsion device 10 with respect to a marine vessel.The methods can include (1) providing an elastic mount 160 a, 160 b thatsupports the propulsion device 10 with respect to the marine vessel; (2)configuring an electromagnet 22 so that increasing an amount ofelectricity applied to the electromagnet 22 increases the shear strengthof an electromagnetic fluid 24 in the elastic mount 160 a, 160 b therebydecreasing elasticity of the elastic mount 160 a, 160 b, and so thatdecreasing the amount of electricity applied to the electromagnet 22decreases the shear strength of the electromagnetic fluid 24 in theelastic mount 160 a, 160 b thereby increasing the elasticity of theelastic mount 160 a, 160 b; and (3) automatically adapting the amount ofelectricity applied to the electromagnet 22 during translation of themarine vessel so as to reduce a likelihood that the propulsion device 10impacts an adjacent structure on the marine vessel as a result of motionof the propulsion device 10 caused by environmental forces includingwind and waves. The methods can further include (4) increasing theamount of electricity applied to the electromagnet 22 when thepropulsion device 10 becomes more likely to impact the adjacentstructure and decreasing the amount of electricity applied to theelectromagnet 22 when the propulsion device 10 has become less likely toimpact the adjacent structure.

According to some examples, the methods include determining thelikelihood that the propulsion device 10 impacts the adjacent structureon the marine vessel based at least in part on a present speed of anengine associated with the propulsion device 10 and a present motion ofthe propulsion device 10 with respect to the marine vessel. According tosome examples, the methods include determining the likelihood that thepropulsion device 10 impacts the adjacent structure on the marine vesselbased at least in part on a present speed of an engine associated withthe propulsion device 10 and a present steering angle of the propulsiondevice 10.

FIGS. 6-14 depict examples of suitable mounts 260 a-260 c that can besubstituted for one or more of the mounts 16 a-16 b shown in FIG. 1.

FIGS. 6 and 7 depict a first example of a mount 260 a according to thepresent disclosure. The mount 260 a is designed to replace the mounts 16a and/or 16 b shown in FIG. 1, which are disposed between connectionpoints of the propulsion device 10 and marine vessel, including forexample at the adapter plate 18 and drive shaft housing 20 of thepropulsion device 10.

In FIGS. 6 and 7, the mount 260 a includes a housing 100, a resilientmember 102 fixed to the housing 100 and an elongated connector 104 thatextends though the resilient member 102. In the illustrated example, theelongated connector 104 is a bolt however the type and configuration ofthe elongated connector 104 can vary from what is shown. The elongatedconnector 104 extends through a through-bore 106 in a hub 108 of theresilient member 102 such that a head 111 on the elongated connector 104is securely clamped against an axial end of the hub 108 when theelongated connector 104 is fastened to the propulsion device 10 in themanner shown in FIG. 1. In the illustrated example, the housing 100 hasa cylinder 112 and opposing flanges 115 with holes 117 for receivingfasteners (not shown) to thereby fasten the housing 100 in place to thepropulsion device 10. The clamp load produced by the connector 104facilitates rotational (torque) loading within the mount 260 a, all asis known in the art.

The resilient member 102 includes radially extending arms 110 that areradially spaced apart and fixed to an inner diameter 114 of the cylinder112, for example by an adhesive or any other suitable form of fastening.The resilient member 102 is made of rubber or other suitable elastomericmaterial such that the resilient member 102 can bend/deflect withrespect to the cylinder 112 under forces from the propulsion device 10and/or marine vessel. A plurality of cavities 116 are defined betweenthe inner diameter 114 of the cylinder 112 and the arms 110 of theresilient member 102. The cavities 116 are interdigitated amongst theplurality of arms 110. Each cavity contains electromagnetic fluid. Thecavities 116 are further defined by (i.e. closed by) a not-showncovering and/or shell and/or axial end plate(s) on the cylinder 112. Anysuitable covering, shell or axial end plate will suffice, as long as thecovering, shell, and/or axial end plate(s) provides a fluid-tight sealon the axial ends of the cylinder 112 so as to enclose the cavities 116and contain the electromagnetic fluid therein.

A fluid circuit 118 connects the cavities 116 to each other so that theelectromagnetic fluid can flow into and between the cavities when theresilient member 102 is deformed under the external forces from thepropulsion device and from the marine vessel. That is, bending ordeforming of the resilient member 102 causes the geometry of each cavity116 to change. In any given deformation, a first group of cavities 116will decrease in size, forcing electromagnetic fluid out of thoseparticular cavities 116. The remaining second group of cavities 116 willincrease in size, creating a vacuum that allows inflow ofelectromagnetic fluid from the first group of cavities 116. The fluidcircuit 118 facilitates the travel of electromagnetic fluid amongst thecavities 116.

The configuration of the fluid circuit 118 can vary from what is shown.As mentioned above, the cavities 116 are defined between adjacent pairsof arms 110. The fluid circuit 118 connects the respective cavities 116so that the electromagnetic fluid is free to flow into and between thecavities 116 when the resilient member 102 is rotationally deformedunder external forces from the propulsion device 10 or marine vessel.

Each cavity 116 has axially aligned sub-cavities 120 (see FIG. 7), whichare separated from each other by a dividing wall 122. The fluid circuit118 connects the axially aligned sub-cavities 120 of each cavity 116with each other so that the electromagnetic fluid is free to flow intoand between the axially aligned sub-cavities when the resilient member102 is axially deformed by the connector 104 under external forces fromthe propulsion device or marine vessel.

In the illustrated example, the fluid circuit 118 comprises a pluralityof fluid passages 124 in the cylinder 112. The fluid passages 124 areconnected to radial holes 126 formed in the inner diameter 114 of thecylinder 112. At least one radial hole 126 is located in each of thesub-cavities 120, which allows flow of electromagnetic fluid into andbetween the respective cavities 116 and sub-cavities 120, as describedabove.

The fluid circuit 118 further includes a manifold 128 (see FIG. 6) thatis remotely connected to each sub-cavity 120 via the above-describedfluid passages 124 and radial holes 126. The configuration of themanifold 128 can vary and in some examples can include a conventionalfluid accumulator to facilitate quick reaction to external forces on themount 260 a and/or a conventional inertia track device. Theelectromagnet 22 is coupled to the manifold 128. As described hereinabove, the electromagnet 22 is configured so that increasing the amountof electricity applied to the electromagnet 22 increases the shearstrength of the electromagnetic fluid in the manifold 128, therebydecreasing elasticity of the mount 260 a. That is, increasing the shearstrength of the electromagnetic fluid causes the fluid to resistmovement (flow) into and between the cavities 116 and sub-cavities 120via the passages 124 and radial holes 126. This decreases the elasticityof the mount 260 a. Decreasing the amount of electricity applied to theelectromagnet 22 decreases the shear strength of the electromagneticfluid in the mount 260 a thereby increasing the elasticity of the mount260 a. That is, decreasing the shear strength of the electromagneticfluid causes the fluid to more easily move (flow) into and between thecavities 116 and sub-cavities 120 via the passages 124 and radial holes126. This increases the elasticity of the mount 260 a.

In the configuration shown in FIGS. 6 and 7, the equally sizedsub-cavities 120 allow for control over the mount's resistance tolateral/axial motion, as well as tipping motions. The four equally-sizedcavities 116 allow for control over the mount's resistance to roll andvertical/horizontal translation motion.

FIGS. 8-11 depict a second example of a mount 260 b according to thepresent disclosure. The mount 260 b is designed to replace the mounts 16a and/or 16 b shown in FIG. 1, which are disposed between connectionpoints of the propulsion device 10 and marine vessel, including forexample at the adapter plate 18 and drive shaft housing 20 of thepropulsion device 10.

In FIGS. 8-11, the mount 260 b has an elongated housing 200 formed froma plurality of housing sections 202, 203, 204 that are axially connectedtogether. A plurality of electromagnets 22 a, 22 b, 22 c are disposed inthe elongated housing 200 and connected to a power source 26 (see FIG.11) to receive electricity, as described herein above.

Resilient members 205 a, 205 b, 205 c are disposed on the electromagnet22 and have radially outer surfaces 206 that are fixed to the innerdiameter 207 of the housing sections 202, 204 by an adhesive or anyother suitable fastener. Although not shown, the interior of the housing200 is enclosed by a covering and/or shell and/or axial end plate(s). Asdescribed herein above with respect to the example in FIGS. 6 and 7, theconfiguration of the covering, shell and/or axial end plate(s) can varyas long as the interior of the elongated housing 200 is sealed in afluid tight manner to retain electromagnetic fluid therein.

The electromagnets 22 a, 22 b, 22 c are disposed in the housing 200 andan elongated connector 208 extends through a through-bore 209 formed inthe electromagnets 22 a, 22 b, 22 c. As explained above, the clamp loadproduced by the connector 208 facilitates rotational (torque) loadingwithin the mount 260 c, all as is known in the art. The electromagnet 22b has a plurality of radial fins 210 are provided in the housing 200. Aplurality of radial baffles 211 extends radially inwardly from the innerdiameter 207 of the center-most housing section 203 and areinterdigitated amongst the radial fins 210. When the resilient members205 a-205 c are axially deformed via the connector 208 under externalforce from the propulsion device 10 or marine vessel, theelectromagnetic fluid is caused to flow into and out of cavities 212formed between the radial fins 210 and radial baffles 211, from cavity212 to cavity 212, around the radial fins 210 and radial baffles 211.The shape and spacing of the radial fins 210 and radial baffles 211defines the shape of the cavities 212 and the pathways for the flow ofelectromagnetic fluid.

The electromagnets 22 a, 22 c further include a plurality of axial fins214. A plurality of axial baffles 216 extends radially inwardly from theinner diameter 207 of the outermost housing sections 202, 2014 and isinterdigitated amongst the axial fins 214. When the resilient members205 are rotationally deformed under external force from the propulsiondevice 10 or marine vessel, the electromagnetic fluid is free to flow incavities 218 formed between the axial fins 214 and axial baffles 216,from cavity 218 to cavity 218, around the axial fins 214 and axialbaffles 216. Thus the shape and spacing of the axial fins 214 and axialbaffles 216 defines the cavities 218 and the pathways for the flow ofelectromagnetic fluid. When rotational motion occurs, the controller 30and electromagnets 22 a, 22 c control the shear strength of theelectromagnetic fluid (as described above) and opposing fins 214 andbaffles 216 rotate with respect to each other and shear theelectromagnetic fluid 24 there between. In this way, the shear strengthof the electromagnetic fluid, as affected by the electromagnets 22 a, 22c, determines the resiliency of the mount 260 b to rotation.

In this example, the housing 200 advantageously is a modular housingconfiguration, wherein the designer can add or subtract housing sectionsfrom the housing 200 to thereby modify the elasticity of the mount 260b. In the illustrated configuration, the outermost housing sections 202,204 control the resistance of the mount 260 b to twisting andvertical/horizontal motions. The innermost housing section 203 controlsthe resistance of the mount 260 b to axial and tipping motions.

FIGS. 12-14 depict a third example of a mount 260 c for supporting thepropulsion device 10 with respect to the marine vessel. The mount 260 cis designed to replace the mounts 16 a shown in FIG. 1, which aredisposed between connection points of the propulsion device 10 andmarine vessel, including at the drive shaft housing 20 of the propulsiondevice 10.

In this example, the mount 260 c includes a housing 300 that includes ametal shell 302 surrounded by a rubber cover 304. An electromagnet 22 isdisposed in the housing 300. A pair of elongated connectors 308 extendsthough a pair of through-bores 310 in the electromagnet 22. Theelectromagnet 22 includes a plurality of radial fins 312. The innerdiameter 311 of the metal shell 302 includes a plurality of radialbaffles 314 that are interdigitated amongst the radial fins 312.Electromagnetic fluid is retained in the housing 300 and free to flowaround the radial fins 312 and radial baffles 314 when the elastic mount260 c is subjected to axial forces along the elongated connectors 308from movement of the propulsion device 10 and/or marine vessel. Cavities316 are defined between the housing 300 and the electromagnet 306 inwhich the electromagnetic fluid resides. As described herein above, theelectromagnet 22 is connected to a battery power source 26 andconfigured so that increasing an amount of electricity applied to theelectromagnet 22 increases the shear strength of an electromagneticfluid in the mount 260 c thereby decreasing elasticity of the mount 260c, and so that decreasing the amount of electricity applied to theelectromagnet 22 decreases the shear strength of the electromagneticfluid in the mount 260 c thereby increasing the elasticity of the mount260 c.

Through research and experimentation, the present inventors haverecognized that certain hydrodynamic handling issues are induced when avessel is turning, usually at medium or high speeds, which creates awobble that is transmitted into the marine vessel. This “wobble” shakesthe marine vessel and is, at the very least, a nuisance, and can evenbecome significant enough to cause safety concerns. The inventors haverecognized that such hydrodynamic handling issues are a complex problemresulting from the relationship between the vessel hull design and thecenter of gravity of the vessel, the center of the gravity of thepropulsion device, and the center of pressure on the gear case. Theproblem occurs on certain boats, at certain speeds, and at certainsteering angles, where a side loading is imparted on one or morepropulsion devices when entering into a turn, which then side loads themounts and causes an imbalance of pressures on the marine vessel 2.

Based upon recognition of the foregoing hydrodynamic handling problem,the present inventors developed the disclosed systems and methods thatautomatically adapt the amount of electricity applied to one or more ofthe electromagnets in the mounting system when a marine vessel isturning and a predetermined threshold oscillation is detected in themarine vessel and/or in one or more of the propulsion devices 10.Namely, the system and method engage a control strategy to limit orcounteract the hydrodynamic handling issue when a set of thresholdconditions are met, including when the marine vessel is at or above avessel speed threshold and is turning at a threshold a turn angle, andwhen a threshold oscillation is measured by a motion sensor in at leastone of the propulsion devices 10 or one the marine vessel 2.

FIG. 16 depicts one embodiment where a marine vessel 2 is equipped witha propulsion system involving three propulsion devices 10, 10′, 10″,which in the depicted example are outboard motors. Each propulsiondevice 10, 10′, 10″ is equipped with a local engine control module (ECM)30 b, 30 b′, 30 b″ in communication with a helm control module (HCM) 30a housed on the marine vessel. Each ECM 30 b, 30 b′, 30 b″ is equippedwith a respective motion sensor 57, 57′, 57″ that measures motion of themarine vessel. Similarly, the system 28 may include a vessel motionsensor on the marine vessel 2 that senses a position and/or angularvelocity or acceleration. As described above, the motion sensors 57, 54may include one or more accelerometers, gyroscopes, and/ormagnetometers. The motion sensors 57 may be placed anywhere on therespective propulsion device 10. In the depicted example, the motionsensors 57 are provided on or in association with the respective ECMs 30b. Similarly, the vessel motion sensor 54 may be provided anywhere onthe marine vessel 2, and in the depicted embodiment is provided on or inassociation with the HCM 30 a.

FIG. 17A provides a graph depicting output of a motion sensor 57, 54 atline 61, which in the depicted example is angular position measured indegrees. In the exemplary representative scenario, the angular positionmeasurements are received by the controller 30, such as by the HCM 30 aportion thereof. The angular position measurement represented at line 61could be from either a motion sensor 57 on a propulsion device 10 orfrom a vessel motion sensor 54 on the marine vessel 2. The controller 30processes the angular position measurement to detect the presence of athreshold oscillation. For example, the threshold oscillation may be apredetermined threshold number of oscillation cycles detected by therespective motion sensor 57, 54 within a predetermined time. Forinstance, and oscillation cycle may be based on peak detection in theangular position measurement. In certain embodiments, the controller 30may also access the magnitude of the oscillations, and the thresholdoscillation detection may further involve detection of a thresholdmagnitude.

In the example of FIG. 17A, the threshold oscillation is detected attime point 63 after three oscillation cycles. Upon detection of thethreshold oscillation, assuming that the vessel speed is sufficientlyhigh and the marine vessel is being turned at a threshold turn angle orgreater, the amount of electricity applied to the electromagnet isincreased to change the elasticity of at least one elastic mountattaching a propulsion device 10 to the marine vessel 2. Line 65represents the power to the electromagnet 22, which is applied at afirst amount until detection of the threshold oscillation, at whichpoint it is increased to a second power amount. For example, the secondpower amount may be a predetermined power increase above the first poweramount. In another example, the second power amount may be apredetermined power value, such as a maximum power rating for therespective elastic mount 160. In other examples, the second power amountmay be a percentage increase over the first power amount, or may be someother power value that is greater than the first power amount. Invarious embodiments, the electricity, or power, increase may beeffectuated as an increase in current or an increase in voltage appliedto the electromagnet in order to decrease the elasticity of the elasticmount, which will have the effect of increasing resistance to andreducing the oscillation of the propulsion device on the marine vessel.In still other embodiments, the second amount of electricity may be anamount determined based on the magnitude of the oscillation.

In certain embodiments, the power increase may be applied based on thefrequency and/or magnitude of the measured oscillation. For example,FIG. 17B depicts an embodiment where the power increase is appliedstrategically to resist oscillation but also avoid transferring motionfrom the respective propulsion device 10 to the marine vessel 2 as muchas possible in order to provide a better experience for the user. InFIG. 17B, line 61 a represents the angular position measurement by themotion sensor 57 on the propulsion device 10, and line 65 a representsthe power provided to at least one elastic mount 160 in the mount system29 supporting the propulsion device 10 on the transom 105 of the marinevessel 2. The power increase is provided strategically to resist theoscillation movement of the propulsion device 10, but the power increaseis removed at the oscillation peaks in order to provide betterelasticity and absorption of the movement of the propulsion device bythe elastic mount 160, and thus to reduce the transfer of motion to themarine vessel 2 at the oscillation peak. Accordingly, the power increaseis applied but is briefly removed so that the lesser amount of power(i.e., the first power amount) is applied at the oscillation peaks.

In the depicted embodiment, the second power amount is applied until thethreshold oscillation of the propulsion device or the marine vessel isno longer detected. In other embodiments, the second power amount may bemaintained for a predetermined time period following determination thatthe oscillation is no longer present. For example, the determinationthat the oscillation is no longer present may include assessment thatthe change in angular position is less than a predetermined amountand/or that the magnitude of the previously-detected oscillations isless than a predetermined magnitude. In still other embodiments, thesecond power amount may be applied for a predetermined time followingdetection of the threshold oscillation, and upon expiration of thepredetermined time the power increase may be removed. If the thresholdoscillation is detected again by the controller 30, then the powerincrease may be reapplied, and in certain embodiments the predeterminedamount of time of application may be successively increased.

Returning to FIG. 16, each mounting system 29, 29′, and 29″, includestwo electromagnetic elastic mounts 160 a and 160 b. In variousembodiments, each mounting system 29 includes any number of one or moreelastic mounts 160. For example, the elastic mounts 160 may be providedin the exemplary mounting system depicted in FIG. 1, which includes fourmounts 16 a, 16 b. As described above, each elastic mount 160 a, 160 bcontains an electromagnetic fluid and an electromagnet arranged suchthat changes in the power applied to the electromagnet will adjust thesheer strength of the electromagnetic fluid and thereby adjust theelasticity of the elastic mount 160 a, 160 b. Each of the elastic mounts160 a, 160 b in each mount system 29 may be controlled separately orsimultaneously and identically. For example, the power adjustments maybe applied to only one of the elastic mounts 160 a, 160 b, or the poweradjustments to the respective elastic mounts may be different inmagnitude or timing. For example, the power increases discussed abovemay be applied strategically to the elastic mounts in order tocounteract the oscillation of the propulsion device 10, such asalternating or otherwise varying the timing at which the power increasesare supplied to each of the elastic mounts 160 a, 160 b in coordinationwith the frequency and/or magnitude of the oscillation.

Similarly, the respective mount system 29, 29′, 29″ may be controlleddifferently from one another. For example, if oscillation is detected inonly one of the propulsion devices 10, 10′, 10″, then only therespective mount system 29, 29′, 29″ may be firmed up by applying acorresponding power increase. Similarly, if the respective mount systems29, 29′, 29″ may be controlled based on the magnitude and/or frequencyof oscillation measured in the respective propulsion device 10, 10′,10″, which could vary between propulsion devices and would result indifferent magnitude and timing of power increases to the one or moreelastic mounts 160 a, 160 b in each of the respective mount systems 29,29′, 29″.

In certain embodiments, the electricity supplied to the mount systems29, 29′, 29″ may be varied based on a vessel angle of the marine vessel2 as measured by the vessel motion sensor 54. For example, a vesselangle over a threshold vessel angle when the marine vessel 2 istravelling at or above a threshold vessel speed indicates that themarine vessel is likely engaged in a banked turn. On certain marinevessels having multiple propulsion devices, one or more of the outerpropulsion devices may lift out of the water during a banked turn. Onsuch a system, it may be desirable to turn off or disable the disclosedcontrol strategy to avoid firming up the mount system 29 for apropulsion device that is out of the water. The propulsion device 10that is out of the water is likely to see sudden changes in load andincreased oscillations as it exits and enters the water, and it may bedesirable to avoid firming up the mount system 29 so that the mountsystem 29 can absorb more of the propulsion device 10 motion andtransfer less to the marine vessel 2. Thus, in certain embodiments, thecontroller 30 may operate to apply no more than the first amount ofelectricity to the electromagnet(s) 22 of certain mount systems 29 whenthe vessel angle of the marine vessel exceeds the threshold vessel angleindicating that the respective propulsion device 10 is on the high sideof the marine vessel 2 and is likely out of the water. Such a strategymay be employed on marine vessels having two or more propulsion devices10 situated on either side of a center line of the marine vessel. Incertain embodiments, such strategies may be employed to control themount systems 29 for the outer-most propulsion devices 10 in propulsionsystem involving three or more propulsion devices 10.

FIGS. 18-21 depict various embodiments of methods 400, 500, 600, orportions thereof, for controlling an elastic mount. In FIG. 18, a method400 of controlling an elastic mount includes receiving a vesselindicator at step 404 while a first power amount is applied to theelectromagnet 22 of a respective elastic mount 160. For example, thefirst power amount may be an amount dictated by a map 60, such as a mapcorrelating a condition of the system to a power amount that is used forcontrolling the elastic mount 160 under normal operating conditions. Thevessel speed indicator received at step 404 may be, for example, avessel speed measured by a vessel speed sensor 41, examples of which aredescribed herein, or a GPS speed determined by a GPS device 43 asdescribed above. For example, the speed threshold may be set at somepercentage of the vessel's speed capability. To provide just oneexample, the speed threshold could be 8% of the maximum speed for thatparticular marine vessel 2 and propulsion system. If the vessel speedindicator is greater than the speed threshold at step 406, then thecontrol algorithm progresses to step 408 and 410 where the turn angleindicator is received and compared to a threshold angle. For example,the turn angle indicator may be one of a steering angle of therespective propulsion device sensed by the steering angle sensor 50associated with the steering actuator for the propulsion device 10. Inanother example, the turn angle may be a steering wheel positionmeasured by a steering wheel position sensor 51 associated with thesteering wheel 31 on the marine vessel 2. The threshold angle is anangle indicating a turn, or at least initiation of a turn, of the marinevessel. To provide just one example, the threshold angle may be 3degrees away from the centered, straight ahead position.

Once the conditions are such that the vessel speed indictor exceeds thespeed threshold at step 406 and the turn angle exceeds the thresholdangle at step 410 the motion of the propulsion device is measured atstep 412 and compared to a threshold oscillation at step 414. If thethreshold oscillation is also detected, in addition to the thresholdturn angle and speed threshold, then a control strategy is implementedwhere the power applied to the electromagnet 22 is increased in order toprovide a firmer elastic mount 160 in order to reduce or counteract thedetected oscillation.

FIGS. 19-21 depict exemplary embodiments of methods for adjusting theelasticity of the mount. In FIG. 19, power is increased at step 416,such as increasing the power applied to the electromagnet 22 by apredetermined amount or to a predetermined power level. At step 418 thesystem checks whether the oscillation is still detected. The powerincrease is maintained at step 420 until the oscillation is no longerdetected, at which point step 419 is executed to return the power levelto the value dictated by the base power map 60 configured to providecontrol during a range of normal operating conditions. In otherembodiments, the increased power may be maintained for a predeterminedamount of time at which point the system may recheck whether theconditions set out at FIG. 18 are still present and, if so, reapply orcontinue maintenance of the power increase.

FIG. 20 depicts another embodiment of method steps for determining andimplementing the power increase. The magnitude of oscillation isdetermined at step 422 and the frequency of oscillation is determined atstep 424. The power increase amount is then determined at step 426 basedon the magnitude of the oscillation. For example, the power increase maybe provided by a map 60 correlating the oscillation magnitude with apower increase amount. The power increase may then be applied at step428 based on the frequency, such as to time the application of the powerincrease to avoid the oscillation peaks, as described above with respectto FIG. 16B. If the oscillation is still detected, the magnitude andfrequency of the oscillation may be re-determined and the power increaseamount and application frequency adjusted accordingly. Thereby, thepower increase will phase out as the magnitude of the oscillationdecreases. Likewise, the frequency at which the power increase is pulsedwill remain timed with the frequency of the oscillation. Once theoscillation is no longer detected at step 430, the system returns tonormal power control at step 432, such as in accordance with a base map60 configured for a range of normal operating conditions.

FIG. 21 depicts another embodiment, which is for a multi-propulsiondevice 10 propulsion system wherein a vessel motion sensor 54 measuresan angle of the marine vessel. The vessel angle is determined at step434. If the vessel angle is within a threshold vessel angle range atstep 436, then all propulsion devices 10 are assumed to be in the waterand the power is increased at step 438 to mount systems 29 associatedwith propulsion devices that meet the conditions depicted at FIG. 18. Incertain embodiments, elastic mounts 160 a, 160 b may be controlledseparately such that the power increase is applied differently to eachof the elastic mounts 160 a, 160 b. If the vessel angle is outside ofthe vessel angle range, then the power increase is not applied to orremoved from any elastic mount 160 in a mount system 29 associated withan outer propulsion device on the high side of the marine vessel(dictated by the direction of the vessel angle), because that propulsiondevice 10 is likely not engaged in the water. So long as the thresholdrequirements set forth at FIG. 18 are maintained, then the powerincrease is maintained until oscillation is no longer detected at step440 in the respective propulsion device, at which time the power controlreturns to the normal power map for that particular mount system 29 orindividual elastic mount 160.

The inventors have further recognized that control of the elasticmount(s) 160 to adjust the elasticity of the mount system 29 can beutilized to address and minimize problems related to “hooking,” wherethe throttle demand sent to a propulsion device 10 is suddenly reducedand the marine vessel slows down rapidly. In such a rapid decelerationscenario, the forces exerted on the propulsion device 10, such as anoutboard, are such that the marine vessel 2 turns as the vessel slowsdown and comes off of plane. This involuntary turn can be problematic,especially in tight quarters where precise vessel control is important.

Through their experimentation and research, the present inventors haverecognized that increasing the electricity applied to the elasticmount(s) 160 during a rapid deceleration of the marine vessel 2 canreduce the problem of hooking. Namely, if the conditions are such thathooking is likely, the controller 30 may increase the power applied toall of the elastic mounts 160 on the propulsion device 10, thusdecreasing the elasticity of that elastic mount and providing a firmersupport of the propulsion device 10 on the marine vessel 2, in order toreduce or avoid hooking.

FIG. 22 depicts one exemplary method 500 of controlling elastic mounts160 in order to prevent or reduce hooking. A first power amount isapplied to the respective elastic mounts 160 at step 502, such asaccording to a base power map 60 configured to address normal operatingconditions. A vessel speed indicator is received at step 504 andcompared to a high speed threshold at step 506. In certain embodiments,the high speed threshold may be a certain percentage of maximum vesselspeed capability. To provide just one example, the high speed thresholdmay be 50% of the vessel's maximum speed capability. In another example,the high speed threshold may be the planing speed for the marine vessel.If the vessel speed exceeds the high speed threshold, the system mayalso check the engine speed at steps 508 and 510 to determine whetherthe engine speed exceeds a high threshold engine speed. In otherembodiments, the engine speed check may be eliminated, and the strategymay be engaged based on the vessel speed alone. A trim position isreceived at step 512, and step 514 is executed to determine whether thetrim position exceeds a trimmed out threshold indicating that the marinevessel is on plane. As long as the vessel speed and/or engine speed, aswell as the trim position, meets the respective threshold, then thesystem waits for a sudden decrease in throttle demand (sometimesreferred to as a “throttle chop”) that could create the conditions tocause hooking. For example, the threshold decrease in throttle demandmay be based on input from an engine load sensor 48 sensing a thresholddecrease in engine load. In other embodiments, the threshold decrease inthrottle demand may be based on input from a throttle position sensor 49sensing a threshold change in throttle positon, such as a thresholdchange in the position of a throttle control lever 39 on the marinevessel 2. To provide just one example, the threshold decrease inthrottle demand may be a 50% decrease in throttle control lever 39position as measured by the throttle position sensor 49. In otherembodiments, the threshold decrease in throttle demand may be higher orlower than that value, and may be calibrated for a particular marinevessel 2 and propulsion system.

Once the threshold decrease in throttle demand is detected, thecontroller 30 increases the power to the electromagnets 22 in one ormore elastic mounts 160 at step 518. In one embodiment, the increasedpower is applied across all elastic mounts in order to prevent theeffects of hooking as much as possible. The power increase is maintainedat step 523 until the boat speed indicator is below a low boat speedthreshold at step 520 and/or the engine speed is below a low thresholdengine speed at step 522. In certain examples, the power increase may bestopped upon detection of either the low boat speed threshold or the lowthreshold engine speed. In other embodiments, such as the depictedexample, both conditions are required. To provide just one example, thelow speed threshold may be 10 miles per hour, or any other speed atwhich the risk of hooking is sufficiently minimized. Similarly, the lowthreshold engine speed may be 1,000 RPM, or some other engine speedindicating that the vessel has slowed enough that the risk of hooking isnegligible or zero. Once the lower threshold conditions are met, thenthe power control returns to the normal power map at step 524.

Through their research and experimentation in the relevant field, theinventors also realized that the elastic mount(s) 160 can be controlledto improve rapid acceleration of a marine vessel, such as to improve the0 to 20 miles per hour acceleration time in a “hole shot” maneuver.Namely, the inventors have recognized that optimum acceleration, such asfrom idle or from a very low speed, is assisted by maximally trimming inthe propulsion device 10. Holding the propulsion device (s) 10 at atrimmed-in angle, where the gear case of the propulsion device 10 istucked in closer to the marine vessel, creates a lift factor that helpsthe vessel come up out of the water more quickly resulting in a fasterinitial acceleration of the vessel, such as from 0 to 20 miles per hour.For example, existing marine vessel trim arrangements for outboardsoften permit a maximum trim-in positon of approximately 4 degrees (seee.g., FIG. 15B). The inventors have recognized that softening the mountsystems 29 supporting the propulsion devices 10 on the marine vessel canallow for additional trim-in, such as another 2 degrees or 3 degrees oftrim-in toward the marine vessel from the normal fully trimmed-inposition. Thus, the control system may be configured such that whenconditions indicate a rapid demand increase, the power supplied to theelastic mounts 160 may be decreased in order to increase the elasticityof the mounts 160 and allow for an increased trimmed-in angle (i.e.,beyond the maximum trim-in provided for by the trim system).

FIG. 23 exhibits one embodiment of a method 600 for controlling anelastic mount in order to provide improved initial vessel acceleration,such as between 0 and 20 mph. The first power amount is applied at step602, such as according to the map 60 for controlling the power to theelectromagnets under normal operating conditions. The vessel speedindicator is received at step 604 and compared to a low speed thresholdat step 606. For example, the low speed threshold may be very low, suchas below 5 mph. In certain embodiments, engine speed may also beexamined to determine whether engine speed is below a low thresholdengine speed, such as below 1,000 RPM, or even idle engine speed orwithin a threshold thereof. The trim position is examined at step 608,such as the value outputted by the trim position sensor 52 or thecommanded trim position from a user or from the HCM 30 a.

At step 608, if the trim position is equal to the fully trimmed-inposition, or max trim-in provided by the trim system, then the systemlooks for a threshold increase in throttle demand at steps 610 and 612.In certain embodiments, the throttle demand may be based on engine load.In such embodiments, the system may further determine whether the engineload is below an engine load threshold, and then look to detect athreshold change in engine load within a predetermined time. In otherembodiments, the threshold increase in throttle demand may be based onoutput of the throttle position sensor 49, similar to that described inembodiments above. If the threshold increase in throttle demand isdetected at step 612 then the power to the electromagnets 22 in one ormore of the elastic mounts 160 is decreased at step 614. For example,the power may be decreased by a predetermined amount or decreased to apredetermined power level. In certain embodiments, the power to theelectromagnets 22 associated with all of the elastic mounts 160 in themount systems 29 on the marine vessel 2 may be decreased to the samepredetermined decreased power level or decreased by the samepredetermined amount.

The vessel speed indicator is monitored at step 616 such that thedecreased power level is maintained at step 618 until the vessel speedexceeds a predetermined high speed threshold, such as the planing speedfor the marine vessel. In the depicted embodiment, the power level isreturned to that indicated by the base power map 60 at step 617 once thevessel speed indicator is greater than or equal to planing speed. Inother embodiments, the power may be slowly increased over time as thevessel speed increases above a threshold vessel speed, so as to phaseout the increased elasticity of the elastic mounts 160 and mount systems29 as the vessel gets up on plane.

In the above description, certain terms have been used for brevity,clarity, and understanding. No unnecessary limitations are to beinferred therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes and are intended to be broadlyconstrued. The different systems and method steps described herein maybe used alone or in combination with other systems and methods. It is tobe expected that various equivalents, alternatives and modifications arepossible within the scope of the appended claims.

What is claimed is:
 1. A method for controlling an elastic mountconfigured to support a propulsion device with respect to a marinevessel, wherein the elastic mount contains an electromagnetic fluid andan electromagnet and is configured such that adjusting an amount ofelectricity applied to the electromagnet changes the shear strength ofthe electromagnetic fluid in the elastic mount and thereby controlselasticity of the elastic mount, the method comprising: applying a firstamount of electricity to the electromagnet to produce an initialelasticity of the elastic mount; determining that a vessel speedindicator exceeds a speed threshold; determining that a turn angleindicator is greater than an angle threshold; measuring an oscillationof the propulsion device or the marine vessel with a motion sensor;determining that the oscillation of the propulsion device exceeds athreshold oscillation; and adjusting the amount of electricity appliedto the electromagnet to change the elasticity of the elastic mount so asto reduce the oscillation.
 2. The method of claim 1, wherein adjustingthe amount of electricity applied to the electromagnet includes eitherincreasing the amount of electricity applied to the electromagnet by apredetermined amount upon detecting the threshold oscillation, orincreasing the amount of electricity applied to the electromagnet to apredetermined value upon detecting the threshold oscillation.
 3. Themethod of claim 1, wherein the motion sensor is located on thepropulsion device and the oscillation is an oscillation of thepropulsion device.
 4. The method of claim 3, further comprisingperiodically removing the electricity adjustment applied to theelectromagnet based on the oscillation of the propulsion device so as toapply the first amount of electricity at oscillation peaks of thepropulsion device.
 5. The method of claim 1, wherein the thresholdoscillation is a threshold number of oscillation cycles in the motionsensor output within a predetermined time.
 6. The method of claim 5,wherein the motion sensor includes at least one of an accelerometer anda gyroscope located on the marine vessel, wherein the oscillation is anoscillation of the marine vessel.
 7. The method of claim 6, furthercomprising determining at least one of a magnitude of oscillation of thepropulsion device and a frequency of oscillation of the propulsiondevice, and wherein the amount of electricity applied to theelectromagnet is adjusted based on the magnitude of oscillation and/orthe frequency of oscillation; and timing an electricity increase basedon the frequency of oscillation.
 8. The method of claim 1, furthercomprising: measuring a vessel angle of the marine vessel with a vesselmotion sensor; removing the electricity adjustment so as to apply nomore than the first amount of electricity to the electromagnet when thevessel angle of the marine vessel exceeds a threshold vessel angle. 9.The method of claim 1, removing the electricity adjustment so as toapply the first amount of electricity to the electromagnet upondetermining that the oscillation of the propulsion device is less thanthe threshold oscillation.
 10. The method of claim 1, wherein the vesselspeed indicator is one of a vessel speed measured by a speed sensor onthe marine vessel and a GPS speed determined by a GPS device on themarine vessel.
 11. The method of claim 1, wherein the turn angleindicator is one of a steering angle of the propulsion device sensed bya steering angle sensor associated with a steering actuator for thepropulsion device and a steering wheel position measured by a steeringwheel position sensor.
 12. A system for supporting a propulsion devicewith respect to a marine vessel, the system comprising: an elastic mountconfigured to support the propulsion device with respect to the marinevessel, wherein the elastic mount contains an electromagnetic fluid; anelectromagnet configured so that increasing an amount of electricityapplied thereto increases the shear strength of the electromagneticfluid in the elastic mount and thereby decreases elasticity of theelastic mount, and further configured so that decreasing the amount ofelectricity applied to the electromagnet decreases the shear strength ofthe electromagnetic fluid in the elastic mount and thereby increases theelasticity of the elastic mount; a motion sensor on the propulsiondevice configured to measure an oscillation of the propulsion device;and a controller configured to: apply a first amount of electricity tothe electromagnet to produce an initial elasticity of the elastic mount;determine that a vessel speed indicator exceeds a speed threshold;determine that a turn angle indicator is greater than an anglethreshold; determine that the oscillation of the propulsion deviceexceeds a threshold oscillation; and increase the amount of electricityapplied to the electromagnet to decrease the elasticity of the elasticmount so as to reduce the oscillation of the propulsion device.
 13. Thesystem of claim 12, wherein the electricity increase applied to theelectromagnet is a predetermined increase added to the first amount ofelectricity upon detection of the threshold oscillation.
 14. The systemof claim 12, wherein the electricity increase is a predetermined amountof electricity applied to the electromagnet upon detecting the thresholdoscillation, wherein the predetermined amount of electricity is greaterthan the first amount of electricity.
 15. The system of claim 12,wherein the threshold oscillation is a threshold number of oscillationcycles in the motion sensor output within a predetermined time.
 16. Thesystem of claim 12, further comprising periodically removing theelectricity adjustment applied to the electromagnet based on theoscillation of the propulsion device so as to apply the first amount ofelectricity at oscillation peaks of the propulsion device.
 17. Thesystem of claim 12, wherein the controller is further configured toremove the electricity increase so as to apply the first amount ofelectricity to the electromagnet upon determining that the oscillationof the propulsion device is less than the threshold oscillation.
 18. Apropulsion system for a marine vessel, the propulsion system comprising:a first propulsion device supported on the marine vessel by a firstmount system comprising at least one elastic mount; a second propulsiondevice supported on the marine vessel by a second mount systemcomprising at least one elastic mount; wherein each elastic mountcontains an electromagnetic fluid and an electromagnet and is configuredsuch that adjusting an amount of electricity applied to theelectromagnet changes the shear strength of the electromagnetic fluid inthe elastic mount and thereby controls elasticity of the elastic mount;a first motion sensor on the first propulsion device configured tomeasure an oscillation of the first propulsion device; a second motionsensor on the second propulsion device configured to measure anoscillation of the second propulsion device; a controller configured to:apply a first amount of electricity to the electromagnet in at least oneelastic mount in the first mount system and the electromagnet in atleast one elastic mount in the second mount system produce an initialelasticity of the respective elastic mounts; determine that a vesselspeed indicator exceeds a speed threshold; determine that a turn angleindicator is greater than an angle threshold; increase the amount ofelectricity applied to one or more electromagnets in the first mountsystem upon detecting that the oscillation of the first propulsiondevice exceeds a first threshold oscillation; and increase the amount ofelectricity applied to one or more electromagnets in the second mountsystem upon detecting that the oscillation of the second propulsiondevice exceeds a second threshold oscillation.
 19. The system of claim18, wherein the first threshold oscillation and the second thresholdoscillation are based on at least one of a position of the propulsiondevice with respect to the marine vessel and a vessel angle of themarine vessel.
 20. The system of claim 18, further comprising, for atleast one of the first mount system and the second mount system,determining that the vessel angle of the marine vessel is within athreshold vessel angle range prior to increasing the amount ofelectricity applied to one or more electromagnets in the respectivemount system.